bug#38387: 27.0.50; [PATCH] vc-hg: use 'hg summary' to populate vc-dir headers

[Daniel Colascione]

> Hi Andrii,
>
> On 26.11.2019 17:16, Andrii Kolomoiets wrote:
>
>> By invoking single 'summary' command we can get more info about
>> repository state: parent revisions, current branch, tags, bookmarks,
>> commit status, available updates and phase.
>
> I guess the questions are:
>
> - Is this output better than the previous one? Hopefully others will
> chime in, e.g. Daniel, who wrote some major improvements to vc-hg a few
> years ago.
>
> - Is 'hg summary' stable enough? Maybe a few years from now Mercurial
> changes its output and this code stops working in all Emacs we'd have
> released in the meantime? This is why we try to use "porcelain" level
> commands (in Git terminology) when possible, not user-level.
>

What's the performance of summary like these days?